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WD Red 4TB NAS Hard Drive Review (WD40EFRX)

Storage is one of the most common concerns of people nowadays, specially if you have an ever growing digital files or data. There are basically two types of storage, the primary storage and the secondary storage. The primary storage is where you usually install your OS and applications. Usually this type of storage is fast or a high performance drive like a 7200RPM drive or a solid state drive. But for your archives, seldom accessed files or collection, you usually store them on a secondary storage drive. Usually secondary storage drives are not as fast as your primary drive, commonly a 5400RPM drive, and they usually consumes lesser power. Today, we are going to look at the WD Red 4TB hard drive designed for NAS system. Basically you can also use the WD Red as a secondary storage inside your desktop PC but it’s really geared towards NAS system. Learn more about the WD Red 4TB NAS drive in my review below.

WD Red 4TB NAS Drive Review

WD Red 4TB NAS Hard Drive Review

Like I said earlier, although you can use the WD Red hard drive series for your backup storage in your desktop PC, the Reds are primarily designed for NAS (Network Attached Storage) systems, whether for home and/or small offices, and can run 24/7 without any problems. The WD Red 4TB drive is also designed for NAS systems which have 1 to 5 bay drives.

The WD Red 4TB features NASware 2.0 technology that basically improves NAS storage performance, increase compatibility, reliability and protects your data if ever a power interruption occurs. With NASware, this makes the WD Red drives very versatile and can be used for most tasks in a small office or home environment, like media streaming, data backup, and many more.

WD Red 4TB WD40EFRX Review-01 WD Red 4TB WD40EFRX Review-02

NASWare also comes with Error recovery controls making RAID configurations much more reliable and significantly reduces RAID errors compared to desktop hard drives. WD Red drives also produce lesser noise and vibration compared to your typical hard drives. The noise or vibration coming from a single drive might not be that loud, but we are talking about several hard drives put together. Noise and vibration may reduce the life span and degrade performance, so it’s important to control and lessen them.

Finally here are other important features of the WD Red NAS drives for system integrators:

  • Streaming Support – NASwareprovides built-in compatibility with the ATA Streaming Feature Set, which is important for AV storage applications such as Windows Media Center.
  • SMART Command Transport (SCT) support – NASwareallows monitoring and measuring of drive performance via the SMART command set. SMART can return data like thermal profiles, drive access statistics and more. NASwarealso delivers temperature accuracy within 1°C.
  • Power Management Support – Enables optimized power usage within the NAS system and protects your data in the event of a power loss or disruption.
  • BIC Performance – Optimized seek to provide BIC performance while reducing the power and acoustics.

WD Red 4TB WD40EFRX Review-05 WD Red 4TB WD40EFRX Review-03

The WD Red 4TB has an IntelliPower rotational speed. You might be wondering how fast is this IntelliPower? Before I answer that, let me define what IntelliPower is. Basically IntelliPower “is a fine-tuned balance of spin speed, transfer rate, and caching algorithms designed to deliver both significant power savings and solid performance.”

So how fast is it? Well, not that fast actually. The WD Red 4TB has a rotational speed of 5400RPM only, whereas the new 5TB and 6TB has 5700RPM. That’s somewhat slow compared to a 7200RPM drive. But again, the WD Red NAS drives are not designed for desktop use and are best used for NAS systems. It’s also important to keep the rotational speed at check to reduce noise, vibration and heat.

The WD Red 4TB also features 3D Active Balance Plus technology. It’s basically an enhanced dual-plane balance control that significantly improves the orverall drive performance and reliability. Hard drives that are not properly balanced may cause excessive vibration and noise in a multi-drive system, reduce the hard drive life span, and degrade the performance over time. Only EFRX models have this kind of feature.

Finally the WD Red 4TB NAS drive has 1 million hours of Mean Time Before Failure, and comes with a longer 3 year warranty compared to your desktop drives. WD Red drives falls in between desktop drives (shorter warranty period and MTBF) and enterprise-type drives that have a longer MTBF and warranty period.

Check out the rest of the WD Red 4TB’s specifications from the table below.

WD Red 4TB NAS Drive Specifications

Specifications6 TB5 TB4 TB3 TB2 TB1 TB
InterfaceSATA 6 Gb/sSATA 6 Gb/sSATA 6 Gb/sSATA 6 Gb/sSATA 6 Gb/sSATA 6 Gb/s
Formatted capacity6 TB5 TB4 TB3 TB2 TB1 TB
Form factor3.5-inch3.5-inch3.5-inch3.5-inch3.5-inch3.5-inch
Advanced Format (AF)YesYesYesYesYesYes
Native command queuingYesYesYesYesYesYes
RoHS compliantYesYesYesYesYesYes
Data transfer rate (max):
Interface speed6 Gb/s6 Gb/s6 Gb/s6 Gb/s6 Gb/s6 Gb/s
Internal transfer rate175 MB/s170 MB/s150 MB/s147 MB/s147 MB/s150 MB/s
Cache (MB)646464646464
Rotational speed (RPM)IntelliPowerIntelliPowerIntelliPowerIntelliPowerIntelliPowerIntelliPower
Reliability/Data Integrity
Load/unload cycles600,000600,000600,000600,000600,000600,000
Non-recoverable read errors per bits read<1 in 10 ^14<1 in 10 ^14<1 in 10 ^14<1 in 10 ^14<1 in 10 ^14<1 in 10 ^14
MTBF (hours)1,000,0001,000,0001,000,0001,000,0001,000,0001,000,000
Limited warranty (years)333333
Power Management
12VDC ±10% (A, peak)1.751.751.751.731.731.2
5VDC ±10% (A, peak)------
Average power requirements (W):
Environmental Specifications
Temperature (°C):
Operating0 to 650 to 650 to 650 to 650 to 650 to 65
Non-operating-40 to 70-40 to 70-40 to 70-40 to 70-40 to 70-40 to 70
Shock (Gs):
Operating (2 ms, read/write)303030303030
Operating (2 ms, read)656565656565
Non-operating (2 ms)250250250250250350
Acoustics (dBA):
Seek (average)282828242422
Physical Dimensions
Height (in./mm)1.028/26.11.028/26.11.028/26.11.028/26.11.028/26.11.028/26.1
Length (in./mm)5.787/1475.787/1475.787/1475.787/1475.787/1475.787/147
Width (in./mm, ± .01 in.)4/101.64/101.64/101.64/101.64/101.64/101.6
Weight (lb./kg, ± 10%)1.65/0.751.65/0.751.50/0.681.40/0.641.32/0.600.99/0.45

Test Setup

In testing the WD RED 4TB NAS Drive, I installed it on an Asus Maximus VII Formula Z97 motherboard, powered by an Intel Core i7-4770K processor. The firmware version is 80.00A80.

The WD Red 4TB was plugged in a SATA 6Gbps port using AHCI (Advance Host Controller Interface). The drive was also not populated with any files, meaning it has a 100% free capacity. Below are the specifications of the test unit.

Operating System: Windows 7 Ultimate 64bit
Motherboard: Asus Maximus VII Formula Z97
Processor: Intel Core i7-4770K
CPU Cooler: Corsair Hydro H105
Memory: Avexir Blitz 1.1 DDR3 16GB 1600MHz
Graphics card: Asus Strix GTX 750 Ti OC
Hard Drive: Kingston HyperX 3K 120GB for the OS and WD RE 4TB for game files
Power Supply: Seasonic X750 Gold Series v3

WD Red 4TB Benchmark Results

HD Tune Pro 5.50
Below are the read/write speed I got while benchmarking the WD Red 4TB with ATTO Benchmark tool. That downward graph is typical in hard drives.

WD Red 4TB ATTO Read Benchmark WD Red 4TB ATTO Write Benchmark

Below you can see some information regarding the drive and the features that it supports.

WD Red 4TB ATTO File Benchmark WD Red 4TB HD Tune Pro Info

CrystalDiskMark Benchmark
The result I got with CrystalDiskMark Benchmark tool was the highest read/write speed I got in all my test. Neither the less, the performance gap is not that far.

WD Red 4TB CrystalDiskMark Benchmark

AS SSD Benchmark
WD Red 4TB AS SSD Benchmark WD Red 4TB AS SSD iops Benchmark

WD Red 4TB AS SSD Copy Benchmark WD Red 4TB AS SSD Compression Benchmark

Anvil’s Storage Benchmark Tool
WD Red 4TB HD Anvil Storage Benchmark Incompressible

WD Red 4TB HD Anvil Storage Benchmark Compressible

Based on the various results I got from benchmarking the WD Red 4TB, it seemed to be performing constantly at around 140MB/s of read speed. That’s very near to its rated speed from its specs sheet. Meanwhile its write speed can fluctuate from around 100MB/s to 140MB/s. But it does handle both incompressible files and compressible files at more or less the same speeds.

Price and Availability

The WD Red 4TB NAS Drive Series is widely available. At the time I published this review, the 4TB (WD40EFRX) model has an MSRP of Php 9,950. But I see some stores selling it for as low as Php, 8,550. So actual street price may be different depending from one store to another. Meanwhile, the 2.5-inch WD Red 1TB (WD10JFCX) has an MSRP of Php 4,350, and the 750GB (WD750BFCX) has an MSRP of Php 3,280. Additional information about WD Red hard drives and limited warranty terms may be found on the company website at

In US, the 4TB capacity currently has a retail price of $169.00 at the time I posted this review. It’s also available in 1TB, 2TB, 3TB, 5TB and 6TB capacities. WD is also offering a 3 year limited warranty and customer support. You can check out the latest pricing and availability below.

WD Red 4TB Review: Conclusion

Performance wise, it is obvious that the WD Red 4TB is not a fast hard drive, but it’s not that slow either. As you can see from the benchmark results from above, read/write speeds are not that fast compared to other hard drives. Its rotational speed is only 5400RPM only, but that’s not constantly running ta 5400RPM since it has IntelliPower technology. Remember, the WD Red is not about speed. It’s about reliability and efficiency.

After benchmarking the drive on my test bench, I then installed the WD Red 4TB drive to QNAP’s latest silent NAS, the QNAP HS-251. It’s has been running 24/7 for several weeks now, and I probably turned off the system around 5 times since for just a few minutes or less than an hour. So far I didn’t encounter any problems or issues until now. Take note, the HS-251 features a passive cooling, but despite that the WD Red still performed well. I also tried accessing several files simultaneously from my desktop PC, laptop and smartphone, and I didn’t encounter any hiccups at all. Large size HD movies were running smoothly even if both devices where accessing it at the same time.

I only have one WD Red 4TB so I cannot comment on its RAID performance. You can check out my WD Red 5TB review for that. But as a single drive, it did perform well. Most of the time, I use the drive to stream media and backup some of my files. The speed of transferring the data from your computer or mobile device to the NAS (and vice versa) also depends on the speed of your router or connection, and probably the performance of your NAS as well. Not all NAS comes with the same specification and features.

Also before getting a WD Red 4TB be sure that your NAS or the NAS that you are going to buy is fully compatible with the drive. This way it would eliminate any problems that you might encounter along the way. But as of today, I haven’t encountered or heard of any NAS system that is incompatible with the WD Red NAS drives.

For its current price and with all the features, this is a great value NAS drive and I can highly recommend the WD Red NAS 4TB for your SOHO (small office / home) NAS systems.


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Peter Paul
Peter is a PC enthusiast and avid gamer with several years of hands-on experience in testing and reviewing PC components, audio equipment, and various tech devices. He offers a genuine, no-nonsense perspective, helping consumers make informed choices in the ever-changing world of technology.

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